<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>

<a href="aa?username=张三">get请求</a>

<form action="aa" method="post">
	<input name="username" value="李四"></input>
	<input type="submit" valu="提交"></input>
</form>

</body>
</html>